Known crawler crane is a mobile crane which installs the lifting operational part on the track chassis and moves by means of crawlers. It can be used to do such works as lifting, transportation, loading/unloading and installation. Crawler crane has the advantages in good lifting ability, low ground pressure, small turning radius, good climbing ability, without landing leg, ability of driving with load, good working stability and freedom in replacement of the height of the girder assembly. It has a wide range of application in construction industry such as electricity project, municipal works, bridges, petrochemical project, water conservancy and hydropower, etc.
The crawler crane needs to be used in conjunction with the counterweight equipment to balance the load according to the lever balance principle, so that the crawler crane may prevent from overturn when it works. The existing counterweight equipment of crawler crane is generally immovable. The crawler crane balances the load by increasing or reducing the weight of the counterweight in order to change counterweight moment of force of the counterweight equipment. In this situation, it is inevitable for the crawler crane to carry large amounts of counterweight. At the same time, it also requires tedious operation when changing the moment of force of the counterweight, which limits the application of the crawler crane, increases the difficulty of the operation and increases the risk of the misoperation.
Therefore, then a crawler crane with a movable counterweight equipment is put forward, such as the technical solution disclosed in “the movable counterweight equipment of crawler crane” (China Patent Publication No. CN20129224Y). Referring FIG. 1, wherein the counterweight equipment 200 is hung beneath the A-frame 9, it controls the distance between the counterweight equipment 200 and the main platform 100 through a drawstring 8, which connects between the main platform 100 and the counterweight 200. However, as the counterweight 200 is hung beneath the A-frame 9, this solution will make the counterweight 200 instable and swing, thus result in unplanned change of the moment of force of the counterweight and unpredictable danger.